True I believe since every person has a different temperature and sound waves.
Answer:
714 nm
Explanation:
Using the equation: nλ=d<em>sin</em>θ
where
n= order of maximum
λ= wavelength
d= distance between lines on diffraction grating
θ= angle
n is 1 because the problem states the light forms 1st order bright band
λ is unknown
d= 
or 0.0000014 (meters)
sin(30)= 0.5
so
(1)λ=(0.0000014)(0.5)
=0.000000714m or 714 nm
here we have to explain the development of the atomic theory by the atomic emission spectrum.
The most important aid in determining the structure of an atom has been study of radiation emitted and absorbed by the elements. The glowing atoms of an element emit radiations.
These are called the atomic spectra. This study helped to understand the structure of the atoms.
To explain the atomic spectra the Bohr's model was introduced. The postulates of the Bohr's model explain the fine spectrum of the atom up to the particle nature of the electrons.
Later some modification on the Bohr's postulates was made to explain the wave nature of the electrons as well. But the atomic spectra is best be understood by the Bohr's atomic model which developed the atomic theory.
Thus the understanding of emission spectrum of atom to develop the atomic theory is explained.
The dichloromethane (DCM) has less density than water and also the polarity of water is much more than DCM. So the mixture of water and dichloromethane will always be a heterogeneous mixture. In the mixture dichloromethane will be always up of the water layer. The volume of the separatory funnel which contains the mixture of DCM and water must have to be more than the total volume of the liquids thus the volume of the funnel will be more than (50+50) = 100mL.
The caution have to consider during the separation are-
1. The separatory funnel have to shake well with lid and have to settle down for some times until the two liquid separated.
2. The lid should be open very slowly as the vapor pressure of DCM is more and it will float on the water.
3. After this the stopcock should be opened and slowly the water will come out first followed by DCM.
A theory is like a hypothesis like an idea. Observation is to gain information like taking notes about what you see.
